WO2019130567A1 - Method for manufacturing lightguide plate - Google Patents

Abstract

The present invention provides a method for manufacturing a lightguide plate, which allows for high-mix low-volume production of easily-handleable lightguide plates for real applications on which shapes such as a dot pattern have been applied with high precision. The method for manufacturing a lightguide plate comprises: a first transfer step of heating a transfer-receiving object between two stampers from the outside of two carriers, applying pressure to the object using a diaphragm press, and thus transferring the surface shape of the stampers to the surface of the object; a second transfer step of continuing to transfer the surface shape of the stampers to the surface of the transfer-receiving object by keeping the temperature of the object between the two stampers from the outside of the two carriers and maintaining the pressure applied on the object; and a step of conveying the transfer-receiving object between the two stampers from the first transfer step to the second transfer step while the object is being held by the two carriers in a substantially sealed condition.

Description

Method of manufacturing light guide plate

The present invention relates to, for example, a back of a liquid crystal display panel such as a smart phone, a mobile phone, a mobile terminal, a personal digital assistant (PDA), a tablet personal computer (PC), a notebook PC, an in-vehicle instrument panel, and a PC display monitor. Manufacture of lights and light guides used inside lighting devices such as, for example, backlights of keyboards such as smartphones, cell phones, mobile terminals, personal digital assistants (PDAs), tablet personal computers (PCs), notebook PCs etc. The present invention relates to a method and a manufacturing apparatus.

A light guide plate that diffuses light introduced from the side and emits light from the surface is used as a backlight of a liquid crystal display panel or the like. In order for the light guide plate to be incident from its side and for the light propagating inside to be emitted from the surface of the light guide plate, a shape such as a dot pattern is generally formed on the surface of the light guide plate.

Lighters, thinner, and less expensive lighting devices are required for lighting devices in which light guide plates are used. Therefore, the light guide plate is required to improve the productivity of such a light guide plate while forming the dot pattern etc. more accurately (while improving the shape impartability) while making the thickness thinner. It is done. A light guide plate is conventionally manufactured by injection molding, extrusion processing, etc., and various devices have been devised.

For example, Patent Document 1 obtains a sheet-like polycarbonate in a molten state, the sheet-like polycarbonate is pressed against a roll having a pattern formed on the surface together with a flexible support; the sheet-like polycarbonate has a flexible support Disclosed is a method of manufacturing a polycarbonate light guide plate including traveling and solidifying on a pattern-formed roll while being supported, and then separating solidified sheet-like polycarbonate and flexible support. See item 1). According to the manufacturing method of Patent Document 1, the shape such as a dot pattern can be accurately given by the manufacturing method, and although the thickness is thin, the light guide plate which has high strength and is easy to handle and which can be practically used can be further reduced. It discloses that it can be manufactured at a price (see Patent Document 1 [0018] and the like).

WO 2017/033290

Therefore, Patent Document 1 describes a method for producing a thinner light guide plate by extrusion, and discloses that the method can produce a thinner light guide plate in which a pattern with a more accurate shape is formed.
By the way, extrusion is generally suitable for mass production of a light guide plate having a pattern of the same shape, since extrusion uses a roll having a pattern formed on the surface, but extrusion is not suitable for various patterns. It is not always suitable for manufacturing the light guide plate in small quantities, that is, for high-mix low-volume production.

Considering the speed of the product cycle in recent years and the short product life, it is possible to produce a large number of products in small quantities. Furthermore, it is a light guide plate that can be given a shape such as a dot pattern accurately and is easy to handle. There is a need for a method of manufacturing a light guide plate that can produce a light guide plate of high strength, preferably at a lower cost and with a small thickness.

As a result of intensive investigations, the present inventors heat the transfer target disposed between the two stampers between the two transports from the outside of the two transports and use the diaphragm-type pressing means. A first transfer step of transferring the surface shape of the at least one stamper by using pressure; and maintaining the heat transfer and holding pressure of the transfer target from the outside of the two conveyance members; A transfer step including a second transfer step of continuing transfer, and a transfer step of transferring the first transfer step to the second transfer step while holding the transferred object between the two stampers in a substantially sealed state by two transfer members; I found a method of manufacturing a light plate. Furthermore, the manufacturing method is capable of producing various kinds of light guide plates little by little, giving shapes such as dot patterns accurately, easy to handle, and practically usable light guide plates, preferably at a lower cost. Despite the small thickness, it has been found that a light guide plate having high strength can be manufactured, and the present invention has been completed.

The present invention provides, in one aspect, a method for producing a new light guide plate, the method comprising
(A) preparing a transferred object disposed between two stampers between two carriers;
(B) Heat the transferred object between the two stampers from the outside of the two transfer members and pressurize it using a diaphragm-type pressing means to apply at least one of the stampers to at least one surface of the transferred object. Transferring the surface shape;
(C) Keep the transferred object between the two stampers warm from outside the two conveying members, hold the pressure, and continue the transfer of the surface shape of the at least one stamper on at least one surface of the transferred object. ;
(D) taking out the transferred object; and (E) holding the transferred object between the two stampers in a substantially sealed state by two transfer members, and transferring from the (B) step to the (C) step Including.

The present invention provides, in another aspect, a novel light guide plate manufacturing apparatus, which comprises:
(I) an arrangement unit for preparing a transferred object arranged between two stampers between two carriers;
(II) Heat the transferred object between the two stampers from the outside of the two transfer members and pressurize it using a diaphragm type pressing means to apply at least one stamper on at least one surface of the transferred object. A first transfer portion for transferring the surface shape; and (III) heat-retaining and holding a transferred object between the two stampers from the outside of the two transfer members, and at least one of the transferred members being at least one surface A second transfer section (IV) for continuing transfer of the surface shape of the stamper; (iv) a take-out section for taking out a transferred object; and (V) a transferred body between two stampers is held in a substantially sealed state by two transport bodies. And a transport unit for transporting from the (II) first transfer unit to the (III) second transfer unit.

The method for producing a light guide plate according to the present invention has the characteristics as described above, so it is possible to produce many kinds of light guide plates little by little, a shape such as a dot pattern is accurately given, and it is easy to handle and practically usable. It is possible to manufacture a light guide plate of high strength, preferably at a lower price and with a thin thickness. Further, in detail, according to the method for producing a light guide plate of the present invention, a light guide pattern provided on a desired area of the thin light guide film surface obtained can be transferred and formed extremely uniformly in the area, and the light guide pattern It is possible to prevent, as much as possible, the occurrence of the misalignment and the warping or breakage of the light guide film.

FIG. 1 schematically shows an apparatus for producing a light guide plate according to an embodiment of the present invention. FIG. 2A schematically shows the operation of the first transfer portion of the manufacturing apparatus of FIG. FIG. 2A shows a state in which both the upper and lower containers are depressurized. FIG. 2B schematically shows the operation of the first transfer portion of the manufacturing apparatus of FIG. FIG. 2B shows that the upper container is depressurized, but the lower container is pressurized, and the upper conveying body is pressed against the upper heating unit by the diaphragm type pressurizing unit. FIG. 3 schematically shows the operation of the second transfer unit of the manufacturing apparatus of FIG. The upper and lower carriers are held between the upper and lower heating means to indicate that they are kept warm and hold pressure.

Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. However, more detailed description than necessary may be omitted. For example, detailed description of already well-known matters and redundant description of substantially the same configuration may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

It should be noted that the following description is provided to enable those skilled in the art to fully understand the present invention, and these descriptions should not be construed as limiting the subject matter recited in the claims. .

A method of manufacturing a light guide plate according to an embodiment of the present invention is
(A) preparing a transferred object disposed between two stampers between two carriers;
(B) Heat the transferred object between the two stampers from the outside of the two transfer members and pressurize it using a diaphragm type pressing means to apply at least one stamper to at least one surface of the transferred object. Transferring the surface shape of (first transfer step);
(C) Keep the transferred object between the two stampers warm from outside the two conveying members, hold the pressure, and continue the transfer of the surface shape of the at least one stamper on at least one surface of the transferred object. (Second transfer step);
(D) taking out the transferred object; and (E) holding the transferred object between the two stampers in a substantially sealed state by the two conveyers, and (B) from the first transfer step (C) [2] Including transport to the transfer step.

In the present specification, the term "light guide plate" refers to what is generally understood as a light guide plate, which diffuses light introduced from the side and emits light from the surface. The light guide plate may be, for example, a back of a liquid crystal display panel such as a smartphone, a mobile phone, a mobile terminal, a personal digital assistant (PDA), a tablet personal computer (PC), a notebook PC, an in-vehicle instrument panel, and a PC display monitor. It is used inside lighting devices such as lights and backlights of keyboards such as smartphones, mobile phones, mobile terminals, personal digital assistants (PDAs), tablet personal computers (PCs), notebook PCs and the like.

The thickness of the “light guide plate” is not particularly limited, and may generally be, for example, 0.1 to 3.0 mm, but it is preferably thin from the viewpoint of downsizing of the display device. . The thickness of the light guide plate is preferably 0.1 to 2.0 mm, more preferably 0.2 to 2.0 mm, and particularly preferably 0.2 to 1.6 mm.

The size of the “light guide plate” is not particularly limited, but may generally be, for example, 50 to 350 × 80 to 600 mm in length, but is 50 to 300 × 80 to 500 mm in length. More preferably, the length is 50 to 250 × the width 80 to 450 mm, and particularly preferably the length 50 to 200 × width 80 to 300 mm.

According to the manufacturing method of the embodiment of the present invention, there is provided a substrate to be transferred disposed between two stampers between two (or a set of) carriers (hereinafter also referred to as “step (A)”) including.
As long as the target light guide plate can be manufactured, the order in which the carrier, the stamper, and the transferred body are arranged is not particularly limited, and after the transferred body is disposed between the two stampers, Furthermore, it may be arranged between two carriers, or two stampers may be arranged between two carriers, and a transfer medium may be further arranged between the two stampers.

In the present specification, the “transferred body” is made of a thermoplastic resin that is plasticized by heating, is flat, and the surface shape of the stamper described later can be transferred to the surface of the transferred body. There is no particular limitation as long as the light guide plate aimed by the present invention can be obtained.

Examples of the “thermoplastic resin” used for the transfer target in the present specification include polycarbonate, acrylic resin, polymethyl methacrylate (PMMA), methyl methacrylate-styrene copolymer resin (MS resin), polystyrene (PS) and cyclo Examples thereof include an olefin polymer (COP) resin, a cyclic olefin copolymer (COC), and a biopolycarbonate resin, a functional norbornene resin, and a copolyester resin, which are main raw materials of isosorbide derived from plants (isosorbide). As a thermoplastic resin, it is preferable to contain a polycarbonate and / or an acrylic resin and the like.

It is preferable that a to-be-transferred body is a film or sheet (Hereinafter, it may be mentioned a "film") of a thermoplastic resin.
In the present specification, the "film or sheet" refers to a thermoplastic resin formed into a thin film.
The thickness and size of the film or sheet are not particularly limited as long as the target light guide plate can be obtained, but the thickness and size of the above-mentioned "light guide plate" can be referred to .

In the manufacturing method of the embodiment of the present invention, in the step (A), two stampers are used, and the transferred object is disposed between the two stampers.
In the present specification, the two “stampers” both have a flat plate shape, and a pattern to be transferred to the surface of the transfer target is formed on one side of at least one of the two stampers, There is no particular limitation as long as the light guide plate aimed by the present invention can be obtained.
The pattern of the stamper is transferred to the surface of the transfer target in contact with the stamper having a pattern formed on the surface.
A pattern to be transferred to the surface of a transfer target may be formed on one side of both stampers. In this case, a pattern is formed on both surfaces of the transfer medium.

It is preferable that the surface of the stamper which is not in contact with the surface of the transfer target and in which the pattern is not formed is a mirror surface.
The surface of the stamper which is not in contact with the surface of the transferred body does not have to have a pattern formed, but it is preferable that the surface is flat and flat, considering that pressure and heating can be performed more uniformly. More preferably, it is even more preferably a mirror surface.

The “stamper” may be made of a material that does not deform or the like when pressing and heating the transfer target, and as such a material, for example, metals such as nickel, stainless steel, copper and iron, hard resin Materials, ceramic materials and the like can be exemplified.

A pattern is formed on one side of at least one of the two stampers, and the shape of the pattern can be appropriately selected according to the target light guide plate. In addition, the size of the stamper can be appropriately selected according to the target light guide plate.

In the present specification, two “conveyors” can hold from the outside two stampers on which the transfer target is disposed, and in particular, as long as the light guide plate aimed by the present invention can be manufactured, There is no limit.

Furthermore, the "conveyor" has a strength that does not break or the like while holding and transporting the two stampers having the transfer-receiving body interposed therebetween from the outside, and further, deterioration or the like when applying pressure and heating described later Preferably not.

The "carrier" may be elongated or sheet-like. When the transport body is elongated, it is preferable because the displacement of the surface shape (positional displacement of the stamper) described later can be further suppressed.
The transport body may be, for example, 0.05 to 0.5 mm in thickness, 0.075 to 0.4 mm in thickness, and 0.075 to 0.35 mm in thickness when it is long. It may be. The width may be 0.5 to 1.0 cm larger, 1.0 to 2.0 cm larger than the largest of the longitudinal and transverse dimensions of the transfer medium and the stamper, and 2.0 ~ 3.0 cm may be larger.

When the carrier is sheet-like, for example, the thickness may be the same as the above-mentioned long shape, may be 0.05 to 0.5 mm, and may be 0.075 to 0.35 mm. It may be 0.075 to 0.4 mm.

Furthermore, it is preferable that the “conveyor” be able to completely cover the transferred object disposed between the two stampers from the outside, and more preferably a sheet (film or sheet). In the present specification, the sheet refers to a thin and wide form.

The carrier preferably carries and carries the two stampers having the transfer body interposed therebetween from the outside, and does not deteriorate when heated and pressurized in the steps (B) and (C) described later. Therefore, the thermoplastic resin sheet, the rubber sheet, the metal sheet, and the like can be appropriately selected.
As a thermoplastic resin sheet used for such a conveyance body, a sheet of resin which is generally considered to have a high usable temperature can be exemplified. For example, biaxially oriented polyester, biaxially oriented polyphenylene sulfide (PPS), cellophane, biaxially oriented nylon, and polyimide can be exemplified. The upper limit of these usable temperatures is generally, for example, biaxially oriented polyester (180 ° C.), biaxially oriented polyphenylene sulfide (PPS) (200 ° C.), cellophane (191 ° C.), biaxially oriented nylon (177 ° C.) ), Polyimide (400 ° C.).

According to the manufacturing method of the embodiment of the present invention, the transferred object between the two stampers is heated from the outside of the two transfer members, and is pressurized using the diaphragm type pressing means to at least one of the transferred members. The surface shape of at least one stamper includes transferring (hereinafter also referred to as “(B) step” or “(B) first transfer step”) on the surface of the stamper.

The transfer target disposed between the two stampers between the two transports is heated from the outside of the two transports. The heating temperature and the heating means are not particularly limited as long as the target light guide plate can be obtained.

In the step (B), the diaphragm is heated to a temperature (also referred to as "the heating temperature in the step (B)") higher than a temperature to which the transferred body can be deformed (also referred to as the "heat deformation temperature"). It is preferable to pressurize using a formula pressurizing means.

In the present specification, the "heat distortion temperature" of a transferee refers to the temperature measured according to the method described in ISO 75, and more specifically, the temperature measured according to the method described in the examples. Say
The “heat deformation temperature” of the transfer target is, for example, 124 ° C. for polycarbonate, 85 ° C. for polymethyl methacrylate (PMMA), 75 ° C. for methyl methacrylate-styrene copolymer resin (80 ° C. for MS resin), and polystyrene (PS) In the cycloolefin polymer (COP) resin, 92 ° C. can be exemplified, and in the case of the biopolycarbonate resin of which plant-derived isosorbide (isosorbide) is the main raw material, 90 ° C. can be exemplified.

In the step (B), the substrate is heated to a temperature (heating temperature in the step (B)) higher than the "heat distortion temperature" of the transfer target.
The heating temperature in the step (B) is preferably higher than the “heat distortion temperature” of the transfer body, but is preferably 80 ° C. higher than the “heat deformation temperature” of the transfer body.

A commonly used heater can be used herein as the "heating means". The heater preferably has a flat surface in contact with the transport body and the like. As a heating means, for example, a cartridge heater and a plate heater can be used.

Two heating means (or heating devices) can be arranged above and below the two carriers. Furthermore, a film-like elastic body of a diaphragm-type pressing means to be described later can be disposed between one of the conveyance bodies and the heating means facing it.
By bringing the transfer body into contact with the heating means, the transferred body can be heated.

Furthermore, the transfer body which is not in contact with the above-mentioned heating means can be pressurized by the film-like elastic body of the diaphragm type pressing means described later to heat the transferred body.
In addition, the film-like elastic body of the diaphragm-type pressing means to be described later is disposed between the carrier and the heating means, and the three members are brought into contact to heat the transferred body through the film-like elastic body. be able to.

Furthermore, the transfer target disposed between the two stampers between the two transports is pressurized from the outside of the two transports. The pressurization is performed using a diaphragm type pressurization means, and the pressure is not particularly limited as long as the target light guide plate can be obtained.

In the present specification, the “diaphragm type pressing means” brings a film-like elastic body into contact with a flat plate-like material (that is, a conveyance body outside the stamper on the outer side of the transfer body). And means for pressurizing by pressurizing with a gas such as air and nitrogen, and is not particularly limited as long as the light guide plate aimed by the present invention can be manufactured. A membrane-like elastic body, gas, pressure and the like can be appropriately selected. It is preferable to use a membrane-like elastic body and pressurize with gas pressure, since more uniform pressurization can be achieved. Furthermore, even if there is some thickness non-uniformity in the stamper and the transferred body, more uniform pressure can be achieved corresponding to the non-uniform shape by using the diaphragm-type pressing means. be able to.
As the “elastic body”, for example, silicone rubber and neoprene rubber (NBR) can be exemplified, and silicone rubber is preferable from the viewpoint of heat resistance.

In addition, pressure can be applied from the outside of the transfer body in a state in which the transferred object between the two stampers is decompressed by using a diaphragm type pressing means. As a result, the influence of air can be reduced, and the thermoplastic resin used for the transferred object can reproduce the pattern shape of the stamper more accurately, which is more preferable.

The pressure applied is preferably 250 to 2000 kPa, more preferably 500 to 1500 kPa, still more preferably 750 to 1250 kPa, and particularly preferably 900 to 1100 kPa.

The heating and pressurizing time may be appropriately selected depending on the heating temperature and the pressurizing pressure, but it is preferably 20 to 150 seconds, more preferably 30 to 120 seconds, and 40 to It is even more preferably 100 seconds, particularly preferably 50 to 90 seconds, most preferably 60 to 80 seconds.

According to the manufacturing method of the embodiment of the present invention, the transferred object between the two stampers is kept warm from the outside of the two transfer members, and the pressure is held to at least one of the surfaces of the transferred object. The transfer of the surface shape of the stamper is continued ((C) step or (C) second transfer step).

The transferred object disposed between the two stampers (14, 16) between the two carriers is kept warm from the outside of the two carriers. As long as a target light guide plate can be obtained, the temperature for keeping warm, the means for keeping warm, etc. are not particularly limited.

In the step (C), it is preferable to keep the temperature lower than the heating temperature of the step (B) and hold the pressure.

The temperature for keeping the temperature is preferably 10 to 150 ° C. lower, more preferably 50 to 140 ° C. lower, still more preferably 90 to 130 ° C. lower than the heating temperature in the step (B), and 110 to 120 ° C. lower Is particularly preferred.
Furthermore, in the step (C), it is preferable to maintain the temperature at a temperature lower than the heat distortion temperature of the transfer target and hold pressure.

A commonly used heater can be used as a heat retention means. For example, a cartridge heater and a plate heater can be used.
Heat retention can be achieved by bringing at least one of the two carriers into contact with the heat retention means. It is preferable to keep warm by bringing both of the two carriers into contact with the keeping means.

The transfer target placed between the two stampers between the two transports is held from the outside of the two transports (21, 25). The pressure of the pressure holding, the pressure holding means, and the like are not particularly limited as long as the target light guide plate can be obtained.

The pressure for holding pressure is preferably 100 to 2000 kPa, more preferably 150 to 1000 kPa, still more preferably 200 to 500 kPa, and particularly preferably 250 to 350 kPa.
For example, hydraulic pressure or pneumatic pressure is preferably used as the pressure holding means. The above-mentioned heat retention means can be used as it is as a pressure holding means.

The heat retention and holding time can be appropriately selected depending on the temperature and the pressure for holding the heat, but it is preferably 20 to 150 seconds, more preferably 30 to 120 seconds, and 40 to It is even more preferably 100 seconds, particularly preferably 50 to 90 seconds, most preferably 60 to 80 seconds.

The heat retention and pressure holding of the transfer-receiving material can be performed, for example, using two of the above-described heat retention means. That is, two heat retention means can be disposed above and below the two transfer bodies, and the heat retention means and the transfer bodies can be brought into contact with each other.

In the step (B), the substrate is heated to a temperature higher than the thermal deformation temperature of the transfer target, and pressurized using a diaphragm-type pressing unit,
In the step (C), it is preferable to keep the temperature lower than the heating temperature of the step (B) and hold the pressure.

In the step (B), the substrate is heated to a temperature that is at most 80 ° C. higher than the thermal deformation temperature of the transfer target, and is pressurized to 500 to 1500 kPa using a diaphragm-type pressing unit,
In the step (C), it is more preferable to keep the temperature 50 to 140 ° C. lower than the heating temperature in the step (B) and maintain the pressure at 150 to 1000 kPa.

In the step (B), the substrate is heated to a temperature that is at most 80 ° C. higher than the thermal deformation temperature of the transfer target, and is pressurized to 750 to 1250 kPa using a diaphragm type pressurizing unit,
In the step (C), it is still more preferable to keep the temperature 50 to 140 ° C. lower than the heating temperature of the step (B) and maintain the pressure at 200 to 500 kPa.

In the step (B), the substrate is heated to a temperature that is at most 80 ° C. higher than the thermal deformation temperature of the transfer target, and is pressurized to 900 to 1100 kPa using a diaphragm type pressurizing unit,
In the step (C), it is particularly preferable to keep the temperature 50 to 140 ° C. lower than the heating temperature of the step (B) and to hold the pressure at 250 to 350 kPa.

The manufacturing method of the embodiment of the present invention includes taking out the transferred body (hereinafter also referred to as “the (D) step”).
The carrier may be removed, and the transferred body may be taken out of the stamper, or the transferred body may be taken out of the stamper without removing the carrier, and as long as the light guide plate aimed by the present invention can be obtained, There is no particular limitation on the method of removing the transfer material.
When the transport body is long, the transport body can be removed by winding up one of the transport bodies.

According to the manufacturing method of the embodiment of the present invention, the transferred object between the two stampers is held in a substantially sealed state by the two transfer bodies and is transferred from the step (B) to the step (C) Also referred to as “process (E)”.

In the manufacturing method of the embodiment of the present invention, the transferred object between the two stampers heated and pressurized in the step (B) is held between the two transfer members (C). It is transported to the process. During the transport, the transfer target is held in a substantially sealed state together with the two stampers between the two transports.

In the substantially sealed state, in the step (B), when the object to be transferred is pressurized using the diaphragm type pressurizing means, the pressure of the object to be transferred is reduced together with the two carriers and the two stampers, and then the two carriers are conveyed. It can be achieved by applying pressure from the outside of the body.

By transferring the transfer target from the (B) step to the (C) step, the (B) step, which is the heating and pressing step, and the (C) step, which is the heat retention and pressure holding step, can be separated. Each can be a dedicated process. Since each can be a dedicated process, a dedicated device can be used for each, and the light guide plate can be manufactured more efficiently.

Furthermore, although the transferred body is transported from the step (B) to the step (C), a shift occurs between the stamper and the transferred body, and the pattern formed on the transferred body is shifted, obscured or uneven. Will not occur. By holding the transfer body and the stamper in a substantially sealed state by using two transport bodies, it is possible to prevent a shift in pattern (that is, a shift in surface shape) and the like.

An apparatus for manufacturing a light guide plate according to an embodiment of the present invention is
(I) an arrangement unit for preparing a transferred object arranged between two stampers between two carriers;
(II) Heat the transferred object between the two stampers from the outside of the two transfer members and pressurize it using a diaphragm type pressing means to apply at least one stamper to at least one surface of the transferred object A first transfer portion for transferring the surface shape of the surface; and (III) heat-retaining and holding the transfer-receiving body between the two stampers from the outside of the two transfer bodies; The second transfer section (IV) for continuing transfer of the surface shape of at least one stamper (IV) a take-out section for taking out the transferred object; and (V) the transferred object between the two stampers in a substantially sealed state by two transports. It includes a transport unit that holds and transports (II) from the first transfer unit to (III) the second transfer unit.

The "carrier", "stamper", "transferred member", "heating", "heating means", "diaphragm type pressing means", "pressing", "described in the manufacturing method of the embodiment of the present invention The "heat retention", "heat retention means", "hold pressure", "hold pressure means", "hold in substantially sealed state" and the like can be applied as they are to the manufacturing apparatus of the embodiment of the present invention.

The manufacturing apparatus of the embodiment of the present invention includes a (I) arrangement portion for preparing a transferred object disposed between two stampers between two carriers.
In the case where the transfer body is long, the placement portion preferably has two unwinding portions of the transfer body, and has a belt conveyor for holding the lower transfer body.

The manufacturing apparatus according to the present embodiment heats the transferred object between the two stampers from the outside of the two transfer members, and applies pressure to the transferred object using at least one surface of the transferred object using a diaphragm type pressing means. And (II) a first transfer portion for transferring the surface shape of at least one stamper.

The first transfer unit includes a diaphragm-type pressing unit and a heating unit. The first transfer portion preferably has separable containers at upper and lower portions. The diaphragm-type pressurizing means has a membrane-like elastic body, and the membrane-like elastic body is disposed immediately below the upper opening of the lower vessel so as to cover the entire opening and is in contact with the membrane-like elastic body of the lower vessel Preferably the heating means are arranged below. It is preferable that a heating means be disposed opposite to the membrane elastic body also in the upper container. The upper container and the lower container preferably both have at least one hole, through which they can preferably be evacuated or ventilated.

It is preferable that the upper container and the lower container can maintain airtightness to the outside of the container when the openings are aligned. In the case where the carrier is sheet-like, it is preferable that the entire carrier including the transferred body can be completely contained in the internal space when the upper container and the lower container are combined. When the carrier is long, even if the carrier is sandwiched between the upper container and the lower container, it is preferable to maintain airtightness to the outside of the container.

(II) It is preferable that the first transfer portion be heated to a temperature (also referred to as a “heating temperature of the first transfer portion”) higher than the thermal deformation temperature of the transfer target, and be pressurized using a diaphragm type pressure unit.

The manufacturing apparatus of the present embodiment keeps the transferred object between the two stampers warm from outside the two transfer members and holds the pressure, and the surface shape of at least one stamper on at least one surface of the transferred object. And (III) a second transcription part.

The second transfer unit includes a heat retention means and a pressure holding means. A heat retaining means can also be used as a pressure holding means. The second transfer portion preferably has separable containers at the top and bottom. It is preferable that a pair of heat retention means be disposed to face each of the lower container and the upper container.
In the second transfer portion, it is preferable that the pair of heat retaining means also serve as a pressure holding means by sandwiching the object to be transferred from the outside of the transfer body.

(III) It is preferable that the second transfer portion be maintained at a temperature lower than the heating temperature of the first transfer portion, and the pressure be held.
Furthermore, it is preferable that the (III) second transfer portion be kept warm at a temperature lower than the heat distortion temperature of the transfer receiving body, and hold pressure.

(II) The first transfer portion is heated to a temperature higher than the thermal deformation temperature of the transfer target, and is pressurized using a diaphragm type pressure unit,
(III) It is preferable that the second transfer portion be maintained at a temperature lower than the heating temperature of the first transfer portion, and the pressure be held.

(II) The first transfer portion is heated to a temperature that is at most 80 ° C. higher than the thermal deformation temperature of the transfer target, and is pressurized to 500 to 1500 kPa using a diaphragm-type pressing unit,
(III) It is more preferable to maintain the temperature of the second transfer portion at a temperature lower by 50 to 140 ° C. than the heating temperature of the first transfer portion, and maintain the pressure at 150 to 1000 kPa.

(II) The first transfer portion is heated to a temperature that is at most 80 ° C. higher than the thermal deformation temperature of the transfer target, and is pressurized to 750 to 1250 kPa using a diaphragm-type pressing unit,
(III) It is still more preferable to maintain the temperature of the second transfer portion at a temperature lower by 50 to 140 ° C. than the heating temperature of the first transfer portion, and maintain the pressure at 200 to 500 kPa.

(II) The first transfer portion is heated to a temperature that is at most 80 ° C. higher than the thermal deformation temperature of the transfer target, and is pressurized to 900 to 1100 kPa using a diaphragm type pressure unit,
(III) It is particularly preferable to maintain the temperature of the second transfer portion at a temperature 50 to 140 ° C. lower than the heating temperature of the first transfer portion, and to hold the pressure at 250 to 350 kPa.

The manufacturing apparatus of the present embodiment includes a (IV) removal unit for removing a transferred object.
The takeout unit preferably has a winding portion of two conveyances when the conveyance has a long shape, and has a belt conveyor for holding the lower conveyance.

The manufacturing apparatus of the present embodiment holds the transferred object between the two stampers in a substantially sealed state by the two transfer bodies, and transfers the (V) transfer portion from the first transfer portion to the second transfer portion. Including.

When the transport body is sheet-like, the transport unit has a device such as an arm, and preferably transports one by one.
When the conveyance body is long, it is preferable to convey using a unwinding part, a winding part, a conveyance roller, etc. using these.
The transport unit may be a transport unit that transports not only the transport from the first transfer unit to the second transfer unit but also the entire manufacturing apparatus from the placement unit to the removal unit.

FIG. 1 schematically shows an apparatus for producing a light guide plate according to an embodiment of the present invention.
The manufacturing apparatus shown in FIG. 1 has a first transfer portion (40) and a second transfer portion (50) having two elongated carriers (21, 25) through which the carriers (21, 25) pass. Have. The conveyance body (21, 25) in the upstream portion from the first transfer portion (40) serves as the placement portion (20), and the conveyance body (21, 25) in the downstream portion from the second transfer portion (50) Double as
Furthermore, the transport body (21, 25) doubles as a transport portion between the first transfer portion (40) and the second transfer portion (50).

The lower carrier (21) is unwound from the unwinding section (22), passes through the roller (23), and is sent on the conveyor (24). The upper carrier (25) is unwound from the unwinding section (26) and passes through the roller (27).
The two carriers (21, 25) pass through the first transfer portion (40) and the second transfer portion (50) together.
The lower transport body (21) is sent on a conveyor (34), passes through a roller (33), and is wound at a winding portion (32). The upper carrier (25) passes through the roller (37) and is rolled in at the winding portion (36).

A transfer target (12) between the two stampers (14, 16) is disposed on the lower transport (21) on the conveyor (24). The transfer target (12) previously interposed between two stampers (14, 16) may be disposed on the conveyor (24), and the stamper (16), the transfer target (12) and the stamper (14) may be arranged. The arrangement may be sequentially performed on the conveyor (24), and the arrangement method is not particularly limited.

A transfer-receiving member disposed between two stampers (14, 16) by appropriately moving a conveyor (24, 34) and rollers, etc. at the same time as unwinding and winding of the transport body (21, 25) (12) is sandwiched between the two carriers (21, 25). Subsequently, by performing unwinding and winding of the two conveyance bodies (21, 25), the transferred body (12) disposed between the two stampers (14, 16) is a first transfer portion (40). Move to

The first transfer portion (40) has an upper container (41) and a lower container (45) which can be separated up and down. The upper container (41) has a vent (42) and can be vented and supplied. A heating means (heater) (43) is disposed in the upper container (41). The lower vessel (45) also has a vent (46) which can be vented and aerated. A diaphragm type pressurizing means (film-like elastic body) (48) is provided near the upper opening of the lower container (45), and a heating means (heater) (47) is disposed therebelow. The upper container (41) and the lower container (45) both have a seal (49), and can be brought into close contact when the openings of both are put together.

With reference to FIGS. 2A and 2B, heating and pressurization in the first transfer portion (40) will be described. While heating both heating means (43, 47) to a predetermined temperature, the interiors of both the upper container and the lower container are depressurized through both vents (42, 46) (see FIG. 2A). Thereafter, when pressure is applied only from the vent (46), the diaphragm-type pressing means (48) lifts the transfer receiving body (12) from the lower side of the transfer body (25) and presses it against the heating means (43) See Figure 2B). Since the upper side of the diaphragm pressurizing means is decompressed, the two conveyance bodies (21, 25) are in close contact with each other.

After heating and pressurizing, the openings of the upper container (41) and the lower container (45) are released.
By unwinding and winding the two conveyance bodies (21, 25), a transfer target (disposed between the two stampers (14, 16) between the two conveyance bodies (21, 25) 12) moves to the second transfer unit (50).

The second transfer portion (50) has pressure holding means (51, 55) having heat holding means (53, 57) on both upper and lower sides. The details of the second transfer portion (50) will be described with reference to FIG. Two heat retention means (53, 57) are heated to a predetermined temperature, and two heat retention means (53, 57) are used from the upper side and the lower side to form two heat transfer means between two transport bodies (21, 25). The transfer target (12) disposed between the stampers (14, 16) is held at a predetermined pressure.

After completion of the heat retention and pressure holding, the transfer target body (12) disposed between the two stampers (14, 16) is unrolled by winding and unwinding the two conveyance bodies (21, 25). 2 Move from the transfer unit to the conveyor (34). At that time, the upper carrier (25) is peeled off by the roller (37), and the transferred body (12) between the two stampers (14, 16) is separated on the lower carrier (21). Taken out.

The present invention provides a light guide plate manufactured by the above-mentioned manufacturing method and having a pattern formed on one side or both sides.
Furthermore, the present invention provides a display device having the light guide plate manufactured by the above-described manufacturing method.

The present invention has a thickness of 100 to 3000 μm made of polycarbonate having an MVR (melt volume flow rate: 300 ° C., 1.2 kg) of 10 to 90 and a weight average molecular weight (Mw) of 16000 to 28000. To provide a polycarbonate light guide plate.
The present invention provides a display device having the above-described light guide plate.

The light guide plate of the embodiment of the present invention is used, for example, inside a lighting device such as a backlight of a liquid crystal display panel and a backlight of a keyboard, and the present invention provides such a lighting device.

Furthermore, such a lighting device may be, for example, a smartphone, a mobile phone, a mobile terminal, a personal digital assistant (PDA), a tablet personal computer (PC), a notebook PC, an in-vehicle instrument panel, a display monitor for PC, etc. Used as a display device, the present invention provides such a display device.

EXAMPLES The present invention will be specifically and specifically described below by Examples and Comparative Examples. However, these Examples are only one aspect of the present invention, and the present invention is not limited by these examples.
In the description of the examples, unless otherwise stated, parts not considering the solvent are based on parts by weight and% by weight.

Example 1
In a 50 cm × 50 cm first transfer container, two horizontally arranged, opposing 48 m × 48 cm wide heating plates were placed.
Between the two heating plates, a diaphragm pressing means having a width of 50 cm × 50 cm and made of a heat-resistant elastic body (reinforcing silicone rubber) is disposed to place the first transfer container in the upper chamber and the lower chamber. It was divided into rooms. Air holes were provided in both the upper and lower chambers of the first transfer container to prepare a first transfer unit.
Two spaced apart pressure metal plates containing a 50 cm × 50 cm heater for heating were horizontally disposed to form a second transfer portion.

Two long resin sheet carriers made of 45 cm wide PET (upper limit of usable temperature: 180 ° C.) are unwound, and the diaphragm pressing means and the upper heating in the first transfer container are passed through the conveyor. Passed between the plates. Furthermore, the two long resin sheet transports were passed between the upper pressure plate and the lower pressure plate in the second transfer portion. Then, the two long resin sheet transport bodies were wound in via the conveyor.

A film of polycarbonate resin (TX0301 manufactured by Sumika Stylon Polycarbonate, weight average molecular weight (Mw): 21,400, MVR: 29, heat distortion temperature: 124 ° C.) of 18 cm long × 14 cm wide × 0.4 mm thick Used as
It measured according to the method as described in ISO75. Specifically, a test piece having a length of 80 mm, a width of 10 mm and a thickness of 4 mm is prepared, and measured under a condition of a load of 1.80 MPa using an HDT Tester 6M-2 (made by Toyo Seiki Seisakusho Co., Ltd.) It was 124 ° C.
Two stampers made of 15 cm long × 10 cm wide × 0.3 mm thick nickel were used. On one of the stampers, a large number of hemispherical concaves 50 μm in diameter and 15 μm in depth were formed entirely on the surface.

A polycarbonate resin film (transferred body) was sandwiched between two stampers. The surface of the stamper having a hemispherical shape on the surface was opposed to the polycarbonate resin film.
A polycarbonate resin film sandwiched between two stampers was placed between the two carriers in front of the first transfer portion. A stamper having a surface shape was disposed below.

The polycarbonate resin film sandwiched between the two stampers between the two carriers was transferred onto the diaphragm pressing means of the first transfer portion. The diaphragm pressing means was in contact with the lower heating plate. The upper and lower heating plates were heated to 180 ° C. to heat the polycarbonate resin film. Once the upper chamber and the lower chamber of the first transfer portion are both depressurized, the lower chamber is pressurized with air to make the polycarbonate resin sandwiched between the two stampers between the two carriers by the diaphragm pressing means. The film was pressed against the upper 180 ° C. heating plate at a pressure of 1000 kPa and heated. The polycarbonate resin film sandwiched between the two stampers between the two carriers is decompressed to be substantially sealed between the two carriers, thereby reducing the influence of air on the polycarbonate resin film due to heating. I was able to The heating time at the first transfer portion was 30 seconds.

The polycarbonate resin film sandwiched between the two stampers between the two carriers was transferred onto the heating plate of the second transfer portion while maintaining the substantially sealed state. Both upper and lower heating plates were heated to 70 ° C. to start keeping the polycarbonate resin film warm. Furthermore, the lower heating plate was raised and held at a pressure of 300 kPa with the upper heating plate. The heat retention time in the second transfer portion was 30 seconds.

The polycarbonate resin film sandwiched between the two stampers between the two carriers was removed from the second transfer portion. Then, the polycarbonate resin film was taken out from the two stampers between the two carriers.
The thickness of the manufactured polycarbonate light guide plate of Example 1 was 0.4 mm.

The following evaluations were made for the light guide plate. The results are shown in Table 1.
The shape of the surface shape was visually observed to observe the pattern of the light guide plate, and the presence or absence of the surface shape was observed. Evaluation criteria are as follows.
There is no deviation (A): There is no deviation of the surface shape.
Substantially no deviation (B): Although there is slight deviation in the surface shape, there is no problem in use.
Deviation is present (C): Deviation of surface shape is evident.

The surface of the transfer ratio light guide plate is divided into 9 in 3 columns × 3 rows, and the center of each divided surface is observed with a laser microscope with a Keyence (product number: LSM-700 manufactured by ZEISS) to obtain each transfer ratio It was measured. The average value of these nine transfer rates was calculated to obtain the transfer rate of the light guide plate of Example 1.
Here, the transfer rate refers to the transfer rate of the height of the hemispherical convex portion formed on the surface of the light guide plate (the dimension of the highest portion from the bottom of the convex portion / the depth of 15 μm of the concave portion).
The transfer ratio of the light guide plate of Example 1 was 99%.

Uniformity of Surface Shape The uniformity of the surface shape was evaluated based on the following evaluation criteria when measuring the transfer rate described above.
When all of the above-mentioned nine transfer rates were within ± 3% of the above (average) transfer rate, it was regarded as very uniform (A).
Although any of the above-mentioned nine transcription rates exceeds ± 5% of the above-mentioned transcription rate, if all are within ± 5%, it was regarded as substantially uniform (B).
When any of the above-mentioned nine transfer rates exceeds ± 5%, it is regarded as defective (C).

The warpage light guide plate was disposed on a plane, and it was visually observed whether the end of the light guide plate was separated from the plane.
There is no warpage (A): the end of the light guide plate is not at all spaced from the plane.
Substantially no warpage (B): the end of the light guide plate is observed to be slightly separated from the plane, but very small.
There is a sled (C): the end of the light guide plate is clearly away from the plane.

Examples 2 to 5
The light guide plates of Examples 2 to 5 were manufactured using the same method as that of Example 1.
However, there are different parts from Example 1, and the details and results thereof are summarized in Table 1.

Comparative Example 1
A polycarbonate light guide plate was manufactured using the same method as Example 1, except that the second transfer step was not performed.

Comparative example 2
A polycarbonate light guide plate was manufactured using the same method as Example 1, except that the first transfer step was not performed.

Comparative example 3
A polycarbonate light guide plate was manufactured using the same method as in Example 1 except that the diaphragm pressing means was not used, and pressing was performed with the upper and lower heating plates.

Comparative example 4
Using the same method as in Example 1, except that the polycarbonate resin film sandwiched between the two stampers is moved in the order of the first transfer portion and the second transfer portion without using two carriers. A polycarbonate light guide plate was manufactured.
The details and results of Comparative Examples 1 to 4 are shown in Table 2.

Considering the embodiment and the comparative example, the transfer is performed in two steps of a first transfer unit having a diaphragm pressing means and a second transfer unit, and the transfer unit is used to transfer substantially from the first transfer unit to the second transfer unit. When transported in a sealed state, it can be seen that it is possible to produce a light guide plate which exhibits a transfer rate of 80% or more and is excellent in the uniformity of the surface shape even if the light guide plate is thin. In the manufacturing method of the embodiment of the present invention, since manufacturing is performed using a stamper, it is possible to change the surface shape for each stamper, and it is possible to easily manufacture a small amount of light guiding plate of various types.

As described above, the embodiment has been described as an example of the technology in the present invention. For that purpose, a detailed explanation is given.

Therefore, among the components described in the detailed description, not only components essential for solving the problem but also components not essential for solving the problem may be included in order to exemplify the above technology. . Therefore, the fact that those non-essential components are described in the detailed description should not immediately prove that those non-essential components are essential.

Moreover, since the above-mentioned embodiment is for illustrating the technique in the present invention, various changes, replacements, additions, omissions and the like can be made within the scope of the claims or the equivalent scope thereof.

In the method of manufacturing a light guide plate according to the present invention, a large number of light guide plates of various types can be produced little by little, which is difficult to cope with the conventional method of manufacturing a light guide plate by injection molding and extrusion. A light guide plate that is accurately applied, easy to handle, and practically usable, preferably lower in price, and can produce a light guide plate of high strength despite its small thickness, so that it can be used industrially Its value is extremely high.

12: transfer target body,
14: stamper,
16: stamper,
20: Placement part,
21: Carrier,
22: Carrier unwinding section,
23: Roller,
24: Conveyor,
25: carrier,
26: Carrier unwinding section,
27: Roller,
30: takeout part,
32: transport body take-up section,
33: Roller,
34: Conveyor,
36: transport body take-up section,
37: Roller,
40: first transfer section,
41: Upper container,
42: vent,
43: Heating means (heater),
45: Lower container,
46: vent,
47: Heating means (heater),
48: Diaphragm type pressurizing means,
49: Seal,
50: Second transfer section,
51: Holding means (metal plate),
53: Heat retention means (heater),
55: Holding means (metal plate),
57: Heat retention means (heater)

Claims (10)

1. (A) preparing a transferred object disposed between two stampers between two carriers;
   (B) Heat the transferred object between the two stampers from the outside of the two transfer members and pressurize it using a diaphragm type pressing means to apply at least one stamper to at least one surface of the transferred object. Transferring the surface shape of
   (C) Keep the transferred object between the two stampers warm from outside the two conveying members, hold the pressure, and continue the transfer of the surface shape of the at least one stamper on at least one surface of the transferred object. ;
   (D) taking out the transferred object; and (E) holding the transferred object between the two stampers in a substantially sealed state by two transfer members, and transferring from the (B) step to the (C) step A method of manufacturing a light guide plate, including:
2. The method according to claim 1, wherein the transfer target is a film of a thermoplastic resin.
3. The method according to claim 1 or 2, wherein the carrier is a sheet of a resin selected from biaxially oriented polyester, biaxially oriented polyphenylene sulfide, cellophane, biaxially oriented nylon, and polyimide.
4. In the step (B), the substrate is heated to a temperature higher than the thermal deformation temperature of the transfer target, and pressurized using a diaphragm-type pressing unit,
   The method according to any one of claims 1 to 3, wherein the temperature is maintained at a temperature lower than the heating temperature of the step (B) in the step (C), and the pressure is held.
5. The method according to any one of claims 1 to 4, wherein a thin light guide plate is manufactured.
6. (I) an arrangement unit for preparing a transferred object arranged between two stampers between two carriers;
   (II) Heat the transferred object between the two stampers from the outside of the two transfer members and pressurize it using a diaphragm type pressing means to apply at least one stamper to at least one surface of the transferred object A first transfer portion for transferring the surface shape of the surface; and (III) heat-retaining and holding the transfer-receiving body between the two stampers from the outside of the two transfer bodies; The second transfer section (IV) for continuing transfer of the surface shape of at least one stamper (IV) a take-out section for taking out the transferred object; and (V) the transferred object between the two stampers in a substantially sealed state by two transports. The manufacturing apparatus of the light-guide plate containing the conveyance part which hold | maintains and conveys from (II) 1st transfer part to (III) 2nd transfer part.
7. The manufacturing apparatus according to claim 6, wherein the transfer target is a film of a thermoplastic resin.
8. The method according to claim 6 or 7, wherein the carrier is a sheet of a resin selected from biaxially oriented polyester, biaxially oriented polyphenylene sulfide, cellophane, biaxially oriented nylon, and polyimide.
9. The first transfer portion is heated to a temperature higher than the thermal deformation temperature of the transfer target, and pressurized using a diaphragm-type pressing unit,
   The manufacturing apparatus according to any one of claims 6 to 8, wherein the temperature is maintained at a temperature lower than the heating temperature of the first transfer portion in the second transfer portion, and the pressure is held.
10. The manufacturing apparatus according to any one of claims 6 to 9, which manufactures a thin light guide plate.

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